A 74-year-old man who plotted to kill his then-wife to start a life with his new lover has been jailed for at least 22 years.
Carol Morgan was found hacked to death at the convenience store she and husband ran in Linslade in 1981.
Detectives at first thought a burglar had killed the mum-of-two as Allen Morgan had an alibi at the time of her death.
Mr Justice Martin Spencer said while sentencing Morgan on Monday: "The brutality of the killing shocked all those who attended the scene.
"Only one person knows the identity of the murderer and that is you, Mr Morgan.
"That is the secret which you have harboured for the last 40 years.